1. Field of the Invention
The embodiments of the invention generally relate to semiconductor devices, and, more particularly, to a field effect transistor (FET) device.
2. Description of the Related Art
Hybrid orientation technology (HOT) provides surfaces for PFET inversion layers and surfaces for NFET inversion layers. A low-cost means of achieving HOT technology results in the device bodies of one type of FET being isolated by oxide (silicon on insulator (SOI)) and the other being physically connected to the bulk wafer. Trigate devices have been shown in HOT but generally lack a means of electrical threshold voltage (Vt) adjustment. Setting the height of the fin in a trigate device on bulk silicon is generally critical because the design requires that the width and the height be controlled to assure full depletion and controlled short-channel effects.
Trigate technology has been proposed for extending scaling of complementary metal oxide semiconductor (CMOS) technology beyond the 65 nm node. Additionally, bulk FinFET integration schemes have been introduced that provide either junction-isolated or oxide-isolated FinFETs. Moreover, as devices physically diminish in size, threshold voltage control by doping generally becomes increasingly ineffective due to dopant fluctuations in the individual devices. Additionally, Vt control is becoming a major barrier to the further scaling of CMOS devices. Therefore, there remains a need for a device which is better capable of controlling threshold voltage in FET devices.